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Updated: Mar 22, 2026

A New Technique for Quantitative Analysis of Hair Loss in Mice Using Grayscale Analysis
Published on: March 9, 2015
Concentric Polycyclic Regrowth Pattern in Alopecia Areata
Lilian Mathias Delorenze1, Maria Fernanada Reis Gavazzoni-Dias1, Marcelo S Teixeira1
1Department of Dermatology, Universidade Federal Fluminense, Niterói, Brasil.
Abstract:
Alopecia areata (AA) is a common form of autoimmune nonscarring hair loss of scalp and/or body. Atypical hair regrowth in AA is considered a rare phenomenon. It includes atypical pattern of hair growth (sudden graying, perinevoid alopecia, Renbok phenomenon, castling phenomenon, and concentric or targetoid regrowth) and atypical dark color hair regrowth. We report a case of AA that resulted in a concentric targetoid hair regrowth and discuss the possible related theories regarding the significance of this phenomenon.
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